Casket (with a little trick)

thingiverse

People struggle with its peculiar mechanism when they think the casket's threads work like most others, so when they turn clockwise to try opening it up, the threads instead get tightened further shut due to their left-handed design. This small box, just 50 by 40 millimeters in size, presents an engaging little puzzle to those trying to open it with the incorrect approach. When faced with its deceptive twist, people instinctively make that common mistake and continue twisting, unknowingly compounding their predicament instead of solving it. By making its left-handed thread such a tiny detail yet significant hurdle, designers created an intriguing product which presents an enjoyable little challenge that leaves even some curious folks bewildered about what's really happening. Many get caught off guard by this small casket, discovering firsthand how left-handed threads don't follow the typical conventions people usually anticipate, thereby causing some to scratch their heads in puzzlement. The cleverly crafted mechanism showcases how much of a delightful twist it brings - both literally and figuratively - as users continue to fumble with trying to open the thing despite repeated failures.